node dotenv won't work with pm2

问题:

I have an application where locally (without pm2) all the environment variables in the .env file work just fine using dotenv.

But on the server where I'm using pm2 to run the app, the environment variables remain undefined.

The pm2 commands I'm using to run the app on server are:

pm2 start myapp/app.js
pm2 startup
pm2 save

回答1:

dotenv will read .env file located in the current directory.

When you call pm2 start myapp/app.js it won't search for myapp/.env.

.env // It will try to load this, which doesn't exist
myapp/
   app.js

So you have two solutions

use path option:

const path = require('path'); 
require('dotenv').config({ path: path.join(__dirname, '.env') });

Or call your script from inside myapp/

pm2 start app.js

回答2:

A good pattern here is to remove dotenv from your code and "require" it on the command line. This makes your code nicely transportable between any environment (including cloud-based) - which is one of the main features of environment variables.

Note: you will still need to install dotenv in your project via npm when running it on a server.

a) code up your .env file alongside your script (e.g. app.js)

b) to run your script without pm2:

node -r dotenv/config app.js

c) in pm2.config.js:

module.exports = {
  apps : [{
    name      : 'My Application',
    script    : 'app.js',
    node_args : '-r dotenv/config',
    ...
  }],
}

and then pm2 start pm2.config.js

note: the use of dotenv/config on the command line is one of the best practices recommended by dotenv themselves

回答3:

you have kill you pm2 process first

try

pm2 kill

then restart pm2 using

pm2 start app.js

回答4:

I use a much simpler version of @Marcos answer:

.env
app.js

for example we need to store token in .env file and pass it right to app.js: inside .env

token=value

inside app.js:

require('dotenv').config();
console.log(process.env.token)

Also, don't forget. If you add .env file to .gitignore and then git pull you repo on VPS or smth, you need to copy .env file manually, otherwise your app won't work.

And in some cases it's important in what area you are using your config, so make sure that NODE_ENV=production string is added to your .env file.

After all you could use pm2 start app.js right from your app's folder.

回答5:

I had the same problem but it wasnt explained clearly so here is the solution based on github user vmarchaud comment. This also fixes the issue people had with @Andy Lorenz solution.

In my case i wanted to create an ecosystem file for multiple apps but i was keep getting

Error: Cannot find module 'dotenv/config'

The solution was easy. You have to declar cwd, aka the project folder where the dotenv/config will be read from.

module.exports = {
  apps: [{
    name: 'app1 name',
    script: 'app1.js',
    cwd: '/path/to/folder/',
    exec_mode: 'fork_mode',
    node_args: '-r dotenv/config',
  }, {
    name: 'app2 name',
    script: 'app2.js',
    cwd: '/path/to/folder/',
    instances: 'max',
    exec_mode: 'cluster',
    node_args: '-r dotenv/config',
  }],
};